Generally, an air mat is an instrument for supplying air to the inside thereof to effect an appropriate cushion force through air pressure, so that a user may rest on the air mat in comfort. As such an air mat can be simple to carry and easily installed in every place, they are widely used.
Especially, the air mat is recently provided with a plurality of embossing air bags formed on the portions abutting against the human body, which provides massaging effects to the user lying on the air mat and reduces unpleasant oppression against him or her.
Most of typical air mats include a cushion part having a plurality of air bags arranged therein, and a lower sheet adapted to be bonded to the lower surface of the cushion part, for tightly sealing the plurality of air bags.
Further, the cushion part or the lower sheet is formed on one side thereof with an air supply hole for supplying air to the inside of each air bag.
Such a conventional air mat is manufactured by means of slush molding in such a manner that plastic resin is first filled in the interior of a mold and is then preheated therein, and after that, when the plastic resin is partially coated to a predetermined thickness on the inner surface of the mold, the filled plastic resin is poured off from the mold and the resin layer having the predetermined thickness is completely gelled and cooled, thereby finishing the cushion part of the air mat.
Next, a plurality of communicating passageways are formed for allowing the plurality of air bags formed in the cushion part to communicate with one another, and the lower sheet that is previously made is then bonded to the lower surface of the cushion part, thereby finishing the whole structure of the air mat.
By the way, the conventional air mat manufacturing method using the slush molding is carried out at a state where the mold is opened on the upper portion thereof according to the characteristics of the slush molding, such that only after the cushion part has been completely molded, the lower sheet can be bonded to the cushion part.
As a result, after the bonding process of the lower sheet with the cushion part is separately carried out, the air mat can be finally made.
More particularly, the bonding process of the lower sheet with the cushion part is conducted by means of high frequency bonding or adhesive bonding. First, in case of the high frequency bonding, a high frequency bonding machine should be separately provided, and also, a relatively long time of period for the bonding process is required, such that the whole manufacturing processes are delayed, thereby making the product costs undesirably raised.
Next, in case of the adhesive bonding, a relatively long time of period for the bonding process is necessary in the same manner as the high frequency bonding, and since the bonding is mostly made by manual operations, it is difficult to provide the firm bonding results of the lower sheet with the cushion part, which results in a low quality of bonding results.
Also, the plurality of communicating passageways should be formed for allowing the adjacent air bags of the cushion part to communicate with each other, such that air can be gently supplied to each of the plurality of air bags.
However, when the slush molding is adopted to mold the cushion part of the air mat, the shape of the cushion part after the molding is very simple, such that the communicating passageways should be made through a separate communicating passageway forming process after the cushion part has been completely molded. Thereby, the whole manufacturing processes are undesirably delayed and the product costs are accordingly raised.
Moreover, since all of the plurality of air bags communicate with one another in the conventional air mat manufactured by means of the slush molding having the above-mentioned problems, it is impossible to partially adjust the cushion forces generated from the air bags.
Especially, in case of a patient lying on the air mat for a long time, he or she should have gentle blood circulation as the oppression of the air bags abutting on his or her body is released partially. However, since all of air bags in the conventional air mat structure communicate with one another, it is really impossible to partially adjust the cushion forces of the air bags.